I think as Hippie has also mentioned, I'll have to go the old school way!!

Because, we don't have a machine shop whom has done such a think ever before, and this will be the first time.
I don't want to do try and errors with a client's engine. Specially that I'm only doing this as a hobby and don't want to get into trouble.

But Glenn, with 400 rods and 350 block 4bolt, and 400 rods, don't I need any other machine job, except the crank journal?

Thanks for your comments, and one more question, would it work with 2bolt main block?